Story stages — edit the idea, not the timestamp

A creator usually thinks in beats—question, intuition, experiment, proof, takeaway—rather than 6.35 seconds. Manic uses the names already written in step(...) as the editing and publishing structure for the movie. There is no second timeline file to maintain.

step("question") {
  show(prompt, 0.4);
  say(caption, "Where does the slope become zero?", 0.35);
}
wait(0.8);

step("experiment") {
  to(tangent, x, 0, 1.8, smooth);
  to(rate, x, 0, 1.8, smooth);
}
wait(0.7);

step("takeaway") {
  rewrite(work, `f'(0)=0`, 0.8, smooth);
}
wait(1.5);

The wait after a step belongs to that stage. This makes a stage export include the transition and the time the viewer needs to absorb its settled result. The next stage begins exactly where its next step begins.

See the story before opening a window

manic stages examples/reactive-world.manic

The report lists every stage’s start, end, and complete duration:

stages — examples/reactive-world.manic (5 stages, 13.55s authored)

  #  stage                  start      end      duration
  1  question                0.00s     2.15s      2.15s
  2  measure-slope           2.15s     5.95s      3.80s
  3  find-the-flat-point     5.95s     8.40s      2.45s
  4  see-the-derivative      8.40s    10.80s      2.40s
  5  takeaway               10.80s    13.55s      2.75s

Use this before recording to catch a rushed hook, an overlong setup, or a takeaway without enough reading time.

Preview one stage

manic examples/reactive-world.manic --stage find-the-flat-point

Manic evaluates the complete persistent world at the stage’s real start, then limits playback and scrubbing to that stage. Nothing is reconstructed as a separate scene, so incoming equation, plot, diagram, and parameter state remain correct.

The live player adds a stage strip above the transport bar:

• click a stage segment to jump to it;
• use 1–9 to jump to visible stages;
• press R to restart at the selected range’s beginning;
• drag the progress bar to scrub only inside the selected range;
• read the current stage and selected range in the HUD.

Record a single stage

The same flag selects the recording range:

manic examples/reactive-world.manic \
  --stage see-the-derivative \
  --record out-derivative \
  --preset reel

For a clean editing clip without the preset’s branding intro/outro:

manic examples/reactive-world.manic \
  --stage see-the-derivative \
  --record out-derivative \
  --preset test \
  --no-brand

Export several stages

Use an inclusive named range when a clip should carry a short story arc:

manic examples/reactive-world.manic \
  --from-stage measure-slope \
  --to-stage takeaway \
  --record out-slope-to-takeaway

--to-stage takeaway includes the whole takeaway stage. With only --from-stage, recording continues through the authored ending. With only --to-stage, it begins at the start of the movie.

Named ranges and numeric --from/--to are intentionally separate. Use stage names for story editing and numeric seconds only for a deliberately precise technical trim. Unknown names report the available stages and suggest a close match.

Recording metadata stays useful

markers.json now includes:

• the selected source range;
• clipped stage intervals with relative t, end, and duration;
• each stage’s original source_t;
• marks and sections filtered to the exported clip and shifted to clip time.

That means narration, captions, music cues, and downstream editing tools can work from zero-based clip timing without losing the position in the source story.

Combine stages with output formats

Stage selection and canvas selection are independent:

manic examples/parameter-journeys.manic --stage takeaway --canvas portrait  --record out-reel
manic examples/parameter-journeys.manic --stage takeaway --canvas square    --record out-square
manic examples/parameter-journeys.manic --stage takeaway --canvas landscape --record out-lesson

The named idea stays the same while the responsive layout changes. Before the batch render, run manic check examples/parameter-journeys.manic --canvas all to review every stage in every supported shape.

Choosing useful names

• Name the change in understanding: see-the-derivative, not show-pink-line.
• Keep a short video to roughly three to six stages.
• Put several synchronized changes inside one stage only when they explain the same idea.
• Add a deliberate wait after the important result.
• Use mark("cue") for an editor timestamp that is not a story stage.
• Use section("Part Two") when the video itself needs a visible chapter card.

Start with Reactive world, run manic stages examples/reactive-world.manic, and preview its find-the-flat-point stage.

Next: Review every format before publishing →